Russia-Ukraine updates: US sanctions Russian military shipbuilder, diamond miner

Russian forces are continuing their airstrikes in the besieged Ukrainian port city of Mariupol, according to the U.K. Ministry of Defense.

"The humanitarian situation in the city is worsening," the ministry said Wednesday in an intelligence update. "Most of the 160,000 remaining residents have no light, communication, medicine, heat or water."

Russian troops have prevented humanitarian access to the southern city, a move the ministry said was as part of a strategy to pressure Ukraine to surrender.

In an interview with MSNBC on Tuesday night, U.S. ambassador to the United Nations Linda Thomas-Greenfield said the United States could not remove Russia from the U.N.'s most powerful body, the Security Council.

"They are a member of the Security Council. That's a fact. We can't change that fact, but we certainly can isolate them in the Security Council," Thomas-Greenfield told MSNBC.

That's separate from the push to remove Russia from the U.N. Human Rights Council, which Thomas-Greenfield told NPR they hope to bring to the U.N. General Assembly for a vote as soon as Thursday.

"I know we're going to get" the necessary two-thirds majority, she told CNN.

Thomas-Greenfield also described what it was like in the room on Tuesday as Ukrainian President Volodymyr Zelenskyy's graphic video finally played for the U.N. Security Council. She told MSNBC it was the first time she saw the uncensored video of the war's victims.

"We were all speechless. We had all seen various videos showing atrocities. But they all covered up the real, you know, the real people that were there - they were all blurred," Thomas-Greenfield said. "This was the first time I've seen that video without the bodies being blurred. And it was horrific. And there was silence in the room. I can tell you that people were horrified."

-ABC News' Conor Finnegan

The U.S. will be sending an additional $100 million in Javelin anti-tank missiles to Ukraine, a White House official confirmed to ABC News. The weapons will be coming from existing military stockpiles.

The White House later released a memorandum from President Joe Biden saying he would be using drawdown powers to release "an aggregate value of $100 million in defense articles and services of the Department of Defense, and military education and training, to provide assistance to Ukraine."

Pentagon officials have said anti-tank weapons provided by the U.S. and other partner countries have been very successful in staving off Russian troops and bogging down vehicle movement.

-ABC News' Justin Gomez

Ukrainian President Volodymyr Zelenskyy reflected on his meeting with the United Nations Security Council in his daily speech Tuesday.

Zelenskyy said the council is "currently unable to carry out the functions for which it was created."

"The U.N. Security Council exists, and security in the world doesn’t, for anyone," he said. "And only one state is to blame for this, Russia, which discredits the U.N. and all other international institutions where it still participates."

Zelenskyy added that Russia "tries to block everything constructive and use global architecture in order to spread lies and justify the evil it does."

"I'm sure the world sees it. I hope the world will draw conclusions," he said.

-ABC News' Christine Theodorou